Reset Procedure w/ out Tool (archive)

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Most of the store bought tools are nothing more complicated than a lenth of wire encased in a fancy piece of plastic. As a result, with a piece of wire you can reset your service lights on the e31 or any other BMW. Am I guessing? No, I regularly reset the service lights on my 850 and M5 and have done so for many years on my previous BMWs. For those less adventureous, purchase the cheapest tool possible ($35) and the following procedure will at least let you know what its doing.

Our e31s have late model service connections (Post-1988 and common to all BMW models). The connection is located next to the radiator overflow tank on the passenger side just in front of the engine (covered by a screw on cap). There are 20 contacts under the cap. The store bought tools simply connect two of these for about 5 seconds to reset the service lights. In effect, it grounds the Service Interval Processor for about 5 seconds. The trick is *knowing* (no guessing here) which pins to connect and for how long. Otherwise its quite simple.

The service indicator lights are reset by connecting pin 7 (Service) to pin 19 (ground). Notet that althrough referred to as "pins," they are actually the female sockets that accept pins). The proper way to do this is to have the ignition off and place a jumper wire between pins 7 and 19. The jumper can be a relatively light guage wire with stripped ends folded to create better contact and simply pushed into the pins.

For those having diffulty locating the pins, there are two rings of pins, one inner and one outer, within the plug. All pins are numbered but you may need a magnifying glass. The #7 pin is in the outer ring at the 6 o'clock position. Easy to find. The #19 pin is in the inner ring at the 9 o'clock position. Do not proceed unless you are sure you have the correct pins!

With the two pins connected, turn the ignition to position 1 (accessory), when the service light goes out, turn the ignition off. The difference between resetting the oil service light and the inpection light is the length of time you have the jumper in place with the ignition on. If you are resetting the oil service light you should turn off the ignition immediatley once the light goes out. If you leave the jumper in too long wtih the ignition on, you will perform an inspection reset as well.

Service light reset tools usually connect three pins of the diagnostic connector: 7, 14, and 19. The connection to 14 is to power the tools flashing lights, etc. Less sophisticated tools have only one switch that connects 7 and 19.

#1 Ignition coil/Motronic
#6 SRS Connector
#7 Service Interval Indicator/Service Interval Processor (Reset)
#11 Starter Signal
#12 Alternator Charge
#14 Battery
#15 Motronic Control Unit
#16 Oxygen Sensor
#18 Motronic Conrol Unit (Programming Voltage)
#19 Ground Distribution
#20 Motronic Control Unit (TXD)

In the new edition of the Roundel magazine,on page 72 there is an article explaining the process of getting those bothersome service indicator lights off such as the ones that say you need to change your oil etc. Instead of having the dealer do it, they say that we can turn them off ourselves with a contraption called "The LiteOff". It is powered by your car battery and covers all BMWs after 1987, 3 thru 8 series. The article doesn't say how much it is but did leave a telephone number to call where you can purchase it. 603-491-1469. I haven't called yet as it's Saturday and I just read the magazine this morning. I would imagine they will be in on Monday...or is that a Holiday?
Kurt

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